Footwear construction typically relies on the manipulation of flat materials into three-dimension shapes in order to form a footwear article. Cloth, leather, or other materials may be cut and sewn or otherwise attached and wrapped around a foot form to create a desired shape for the article, such as a footwear upper.
The Inventors have recognized several drawbacks with this traditional approach. For example, the material used to construct the upper may have only limited degrees of freedom in terms of flexibility, thereby limiting the ways in which the upper conforms to a wearer's foot and reducing comfort. As a result, even after the footwear is worn for a considerable amount of time, it may still not fully conform to the actual contours of the wearer's foot.
To at least partially address the above issues, the inventors herein have taken alternative approaches to footwear construction. In one approach, at least a portion of the upper is formed via a plurality of intertwined cords. For example, the upper may be formed from more than one uninterrupted cords engaging with itself and/or one or more additional cords at a plurality of intertwined, yet at least partially slipping, locations. Due to the slippable intertwined connections between cord sections, the overall shape or contour of the upper portion can change, while at the same time remain flexible. In this way, the upper portion can conform to a wearer's foot with ease, while remaining highly flexible and still providing support.
In another example, a footwear article may include a looped upper with fibers or cords formed into a structure. In one example, the cords in the upper may be in slippable engagement with respect to one another and may be engaged at interfaces with a sole. The cords in the upper may also be interlocked with one another. The slippable engagement may be formed at cord interfaces, the interfaces positioned along a loop line traversing across lateral and medial sides of the upper, and further across a forefoot and/or toe region. The looped upper may be formed in various grid-like patterns. The fiber or cord may comprise grasses, flaxes, and other fibrous plant material. Further, it may comprise artificial polyamides such as nylon, although organic polyamides may also be used. Still further the cord may comprise a polymeric material.
By providing a looped upper with cords slippable relative to one another in the upper, yet having reduced slip at a sole, it is possible to retain a functional footwear article that retained to the wearer's foot, while enabling the upper to form fit to the wearer's foot. For example, the slip between the various cord interfaces enables each cord section between an interface to have a variable length so that the overall upper conforms to the actual shape of the wearer's foot.
It should be appreciated that although described in regards to slippable interfaces, there may be some embodiments and/or portions of the upper where slippage is limited (controlled) and/or prevented as it may not, in some embodiments, be needed or necessary. For example, and not as a limitation, controlled slippage may be provided corresponding to a desired limitation on motion. For example, controlled slippage may be provided to address quick lateral movement where some slippage is provided but limited in distance and/or time. Further, in other embodiments, one or more regions of the upper may be configured for non-slippage, creating a more rigid, non-slip or limited slip interface. As an example, the range of slippage may be controlled by one or more of the slippable interfaces, the length of the cord sections, etc. Further, the type and position of the cord sections and interfaces may further be used to provide controlled slippage.
In another example, a footwear article may comprise a sole coupled to a cord structure. The cord structure may include interconnected bights in a vamp cord and a rand cord forming a loop line extending along at least a portion of the footwear article. The vamp cord and rand cord may each be formed via one or more uninterrupted cords.
Interconnecting bights in the cord structure enables a 3-dimensional form fitting structure to be provided in the footwear article. The connection between the bights can increase the range of motion and freedom of movement of the cord structure when compared to other footwear articles using sewn material which are wrapped around a foot form. As a result, the shape of the cord structure may adjust and conform to a foot with minimal wearing. Consequently, the footwear article's comfort is increased.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.